The candidate is a recently independent physician-scientist who has shown strong commitment to biomedical research. His long-term career goal is to develop a strong research program in molecular mechanisms of airway inflammation. His immediate research goals are to understand the molecular mechanisms of regulation NO synthesis by inducible nitric oxide synthase (iNOS) in airway cells and devise methods to control it. A successful R01 application has the candidate poised to continue his current studies, initiate new programs, acquire new skills and build new collaborations. The K02 award is needed to reduce the clinical component of the candidate's current appointment, thus allowing a period of intensive research focus to foster his scientific development and expand his potential to make significant research contributions. The candidate is in a highly supportive environment with excellent mentors and numerous opportunities for intellectual development. He is a faculty member of a newly established center for "Biology of Inflammation". The candidate's laboratory is within the center and its core laboratories, which comprise 20,000 sq, ft. of newly renovated state-of-the-art-open lab design facilities. The center's research environment offers a dynamic critical mass of investigators providing a synergistic environment for the candidate's research. The overall objective of the core research project (a five-year R01 funded 8/1/02) is to understand the mechanisms of iNOS degradation in airway epithelial cells. It consists of four specific aims: 1) Identification of human iNOS degradation pathway. 2) Characterization of possible role of ubiquitination in iNOS degradation. 3) Elucidation of the subcellular localization of human iNOS. 4) Analysis of modulation of iNOS degradation by allosteric inhibitors. The candidate is addressing three additional specific aims through collaborative studies: I) Determination of specific sites of iNOS ubiquitination. II) Elucidation of Role of phosphorylation in iNOS ubiquitination. III) Identification of specific ubiquitin ligase (E3) responsible for iNOS ubiquitination. Studies will be conducted in epithelial cell lines and in primary airway bronchial epithelial cells. The rational for the proposed studies is that once the degradation mechanisms of iNOS are understood, therapeutic strategies can be designed to alter these pathways and modulate iNOS degradation. The results of these studies will increase our understanding of the cellular process of iNOS regulation and thus lay the groundwork for future studies aiming at controlling NO synthesis in diseases of airway inflammation such as asthma.